Method oe and apparatus por cooling and ventilating



May 3 9 L, 1.. LEWIS METHOD OF AND APPARATUS FOR COOLING AND VENTILATING Original Filed Dec. 22, 1924 ATTORNEYS.

Ill

Reissued May 3. .1927,

Re.16,6l1 UNITED srATEs PATENT orrles.

LEO LEWIS, or'rnamrmnnnaw JERSEY, ASSIGNOR TO CARRIER ENGINEERING CORPORATION, OF NEWARK, NEW JERSEY.

marl ion or am) arrana'ros ron-coonme AND vmrrinarine.

Original iio. 1,583,060, dated lay 4', 18, Serial No. 757,889, filed December 22, 1924. Application for reluae filed. February 12, 1927. Serial 119,167,854.

This invention relates to the cooling and ventilating of rooms or buildings and hasreference more, articularly to amethod of and apparatus or'cooling and ventilating which is especially adapted to be used in rooms or buildings where people congregate, such as theaters, auditoriums, assembly rooms, schools, and other enclosures occupied by people in considerable numbers.

For the greatest comfort of people assembled in such places, it is desirable to maintain acomparatively low relative humidity ofthe air, preferably not greater than about 50 percent, since a high relative humidity causes greater discomfort than'alower relativehumidity with a higher temperature. It is also desirable, especially in the summer months to maintain'the room temperature and humidity as low as practicable and keep the air circulating so asto quickly absorb the heat and moisture from the bodies and exhalationsof-the'peo he in the room. It is also important that t e air admitted through the supply ducts or the like near persons in the room should not have a 'ten'iperature more than about 8 degrees lower than the average: room tempera ture or said air current will cause discomfort to the individuals.

In ventilating and cooling systems for similar purposes, as he-retofore designed, the greater part of the airwhich is recirculated is passed through a dehumidifier where its temperature is reduced as much as degrees to degrees below the dry bulb temperature in the room in order to reduce the relative humidity of the air which has been unduly raised as a result of the moisture respired and evaporated from the bodies of the people inlthe room. As theair at this low temperature was too cold to reintroduce into the room containing the people without discomfort to the latter, said air had to be reheated at additional expense so that the'system is expensive to operate as to cost of refrigeration and heating. This method moreover, requires the operation of a boiler during the summer season, which is f ll objectionable.

An object of this invention is to produce a. practical and eiiieient cooling and ventilatings stem for theaters and other enclosures in which people congregate in considerable numbers, in which a desirable temperature and relative humidity are maintained the.

enclosure regardless of the number of people therein, and in which the air for ventilating and cooling is su plied to the enclosure with the greatest com ort to thepeople therein.

Other objects of the invention are to produce an efiicient cooling and ventilating systemwhich is economical in operation, and

[can be installed with a'minimum initial investment; also to provide a cooling; and ventilating system in which the bulk ofithe air is reclrculated without being conditioned,

and only a small part of the air supplied blended or mixed with the recircu ated air.

to produce a mixturehaving-a sufficientlylngh temperature so as not to produce discomfort to the occupants when'the mixed air is introduced into the enclosure; also to cause the requisiteamount of vitiated air containing moisture 'eva orated and respired from the persons to be discharged out of the enclosure instead of being passed through the dehumidifier, thus saving in refrigerat1on; also to provide a system of the class described in which the admission of fresh air from the outside and the relief .ofvitiated air from the enclosure are automatically regulated so as to maintain the desired conditions of temperature andrelative humidity in the enclosure, and also to improve cooling and ventilating methods and apparatus in other respects hereinafter specified and claimed.

In the accompanying drawings:

Fig. 1 is a'diagrammatic sectlonal elevation of a building equippedwith apparatus embodying m -'nvention for carrym out my improve cooling and 'venti ating method. a

Fig. 2 is a diagrammatie'view of the damper mechanism thereof.

The drawings illustrate an arrangement of apparatus suitable for a theater building 10, of ordinary construction, having a stage 11, a balcony 12, and a main auditorium 13.

The balcony 12 and auditorium 13 are provided, as usual, with seats 14 under which are shown ventilators of the mushroom vtype 15 connected by openings through the floor to a ventilating chamber or passage 16 under the balcony 12 and to a corresponding ventilating passage or chamber 20 under the auditorium.

In the preferred arrangementillustrated, the air conditioning or cooling apparatus is located in a chamber or space 21 above the balcony, and the air is introduced at the upper ortions of the occu ied spaces and with rawn at the floors. t should be understood, however, that the arrangement may be reversed and the air introduced at the lower portions of the occupied spaces and exhausted at the upper portions thereof. With the arrangement shown, however, considerably less air is necessary for the proper ventilation of the enclosure. .In ""some cases the decorations 1n the building or other structural features would prevent the location of the, apparatus as shown.

According 'to my improved ventilating and cooling method, the greater portion of 'the air, preferably not less than about 75 percent of the air withdrawn from the enclosure is recirculated and returned to the enclosure, the remaining smaller port-ion being allow to escape into the atmosphere.

The air thus exhausted into the atmosphere is replaced by taking a corresponding vol ume of fresh air from the outside and dehuniidifying or conditioning the fresh air to the required dew point, so that by then mixing this conditioned air with the warmer recirculated a1r,.a resultant air mixture having a temperature of about 72 degrees-F. and a sufiiciently low relative humidity. is obtained, and this mixed air is admitted into the enclosure.

The heat given off byeach erson in the room amounts to approximate y 4 B. t. 11.

per minute and there will be respired from and evaporated from the body of each personabout 0.1 pound of water per hour; The

volume of air supplied to the enclosure, 7 therefore, is such that by properly regulating the proportions of conditionedand recirculatedyainthe temperature in the enclo-" sure will not increase above 80? 'F. and the relative humidity will not exceed'about 50 percent notwithstanding the heat and mois- 'fort to the people inthe room. It is important that a -low relative humidity bemaintained, preferably not exceeding about 5.0 percent, especially during the summer months when a high relative. humidity is more oppressive than a high: temperature.

The proportions of fresh air" and rcircu lated air can be varied over fairly wide limits and in fact the apparatus to be described is adapted to automatically vary 23. In warm weather, when it is necessary to cool and dehumidify the air,- the spray water is cooled by suitable refrigeration apparatus, not shown. The air conditioner 22 is equipped with a dew point control indicated at 23- of any known or suitable type dapted to regulate the temperature in the conditioner, so that the air leaving the same will have the required predetermined dew point. For example, during the summer months when dehumidification is required, this control is adapted to regulate the volume of refrigerated water admitted to the em ay s, while during the winter months the control is adapted to regulate the supply of steam for heating the spray water. Dew point controls of this nature are well known. From the dehumidifier 22, the air passes through a mixing chamber 24 connected to thesuction side of a main blower or fan 25.v

The dehumidifier 22 is connected'by a duct 26 to a fresh air inlet, such for example, as an air admission'tower 27 preferably located on the roof of thebuilding, and a heater or tempering coil 28 ispreferably located between the duct 27 and dehumidifier 22, said heater being supplied by steam through a pipe 29 so as to temper the. air from the outside before it enters the dehumidifier. This tempering coil is simply to relieve the work of the usual automatic'dew point control. of thedehumidifier 22,an d is only necessary in cold weather. The steam admitted through the pipe 29 can be controlled either by hand or automatically by a thermostat located in the fresh air duct 26, as desired.

The cool fresh :air passing through the dehumidifier 22 passes into the mixing chamber 24: where it is preferably mixed with a much larger volume of the air withdrawn from the room and returned-through a duct 30. The duct 30 connects at one end with the discharge of a blower 31, which is. connected to a suction duct 32. The duct 32,

as shoWnhasIa branch 33 leading from the exhaust chamber 16,0f the balcony l2 and a branch -34 leading from the exhaust chamber 20 of the auditorium 13.

Theother end of the return duct 30 has a branch 35 leading to 'a relief tower 36, preferably located on the roof of the building, and 'alsecond branch 37- connecting with the mixing chamber'24 so that the recirculated air or therequired portion thereof 2 men can be thorou hly mixed with the fresh air passing into t e mixing chamber 24 through thedehumidifier 22. The mixing of the two grades of air is made more complete by passing the mixture through the blower 25, the churning action of which accomplishes a perfect mixture. The discharge duct 38 of the blower 25 is provided with a branch pipe 39 which delivers its air into the apt per portion of the space above the balcony 12, and a second branch 40 connected. to a register or outlet 41 located so as to deliver air into the upper part of the auditorium.

In the summer months .itwill ordinarily not be necessary to heat the air after "passing through the blower 25, owing to the fact that the mixture of the small percentage of coldfresh air with the larger percentage of recirculated air produces a resultant temperature of the mixed airv which is suitable for admission into the room. However, in

1 the winter months it may be necessary to heat the air delivered to'the room, and for this or se a'heater 42 is provided in the supply (not 39, anda heater 43 in the duct .40, said heaters bein supplied 'by-steam .43 respectively. A thermostat 46 is provided in the exhaust duct 34 and a thermostat .47 is located in the exhaust duct 33 from the balcony 12. A diaphragm valve 48.is provided on the steam pipe 44 and a dia hragm valve 49 on the steam pipe 45, sai diagphragm valves being connected by air lines or otherwise to the thermostats 47- and 46, respectivelv 'so that the temperature of air exhausted from the balcony and auditorium regulates auto.- matically and independently the tempera= ture of air introduced to said balcony and auditorium. Any other suitable thermostatic re lating means for similarly controlling die heaters could beemployed.

For'.controlling the relative humidity in the room, a suitable hygro'st-at or device 50 responsive to changes in humidity is positioned preferably in the return duct 30, .F'O as to be influenced by the air exhausted from the room. This hygrostat 50 is operatively connected as by an air pressure line 51, with a motor 52 which'is connected by actuating mechanism to dampers53, 54 and controlling respectively the fresh air admission duct 26, the relief air duct'35 and. the branch through pipes 44 and return duct 37 connecting with the mixingchamber 24. The "dampers can be of any suitable kind, and the 'connectionsbetween the motor 52 and the'dampers 53, 54 and 55 can be of any sort such as the lever. link and rod connections 56 shown in Fig. 2,

whereby when the motor 52 closes the dampers 53, the dampers 54 will also simultaneously'and correspondingly close and the dampers 55 will open, and vice versa. Thus the motor 52 operates to admit an amount of fresh air to the dehumidifier which may percent.

In the operation of the systei'n, the two thermostats 46v and 47 are set at the minimum temperature, which preferably would be about 68,'and this minimum temperature would be maintained so long as the house or enclosure remains empty, or when it contains only a very few people. The hyqrostat-ISO is adjusted to control at the desired relative humidity which ordinarily will be 45 percent to 50 percent, say 50 lVhen the enclosure is empty, the dew point of the air in it will be determined by the point at which the dew point control of the dehumidifier 22 is set. If the hygrostat 5(l is set for 50 percent relative humidity,-and the thermostats 46, 47 set for a minimum temperature of 68 F. then the dew point control of the dehumidifier would be set for 49 E, which is the dew point required for the fresh air leaving the dehumidifier 24 to produce 50 percent relative humidity at 68 in the enclosure. With no people in the house, all of these controls would be in equilibrium and dampers 53, 54 would be closed or'nearly closed, so that no fresh air would be admitted, or else possibly only a predetermined minimum supply which might be as little as 10 percent of the total voluine handled by fan 25.

The effect which would becaused by people entering either the auditorium or the balcony would be two fold; first to raise the temperature of theair, due to bodily heat, and second, to increase the dew point. due to the moisture evaporated from their bodies and carried bv res ired air. Both of these conditions affect tie air passing over the hy rostat 50. The rise in dry bulb temperature tends to reduce the relative humidity of the air, and the increase in dew point tends to offset thatreduction.- but the effect of the change in the dry bulb temperature is much greater-than the other. When the hygrostat 50 is so affected, it is thrown out of equilibrium and opens the dampers 53 and 54 the necessary amount and correspondingly closes the dampers 55 sothat a greater volume of fresh air is admitted through the dehumidifier 22. This gives a greater cooling ca ac'it-y to absorb'the additional heat and 0 sets the moisture given off by the people. As-the number of people increases,

the dampers 53 and 54 will gradually opened more and more until the'full capac ty of the dehumidifier 22.'has been reached. The hygrostat '50 functions in the same manner, regardless of whether steam Velivring the m x ail I 0 {he 'wr'a tying the pro ortions -o'f .cqmf tnblef f fo'l fi i b .3 1

hich lp'n'na ef 12 1 9ni \i'if l'1c1'1'iiu 'lif'; ii king fresh an Wlth alr wlt-hdrawn from theem regulating the amount of air relieved into the atmosphere and the amount of fresh air taken from the atmos here under the control of the relative humi ity inthe enclosure 7. The method of ventilati an enclosure in which people assemble, w ich includes withdrawing air from said enclosure, conditioning fresh air'to provide air having a dew oint lower than the dew point of the withrawn air, mixing said conditioned fresh air with air withdrawn from the enclosure, and deliveringl the mixed air' to the enclosure, varying t e proportions of said fresh air in the mixture in accordance with changes in the number of people in the enclosure, and

Eegulating' the temperature of the mixed air ivered into said enclosure under control of the temperature of the air withdrawn from said enclosure.

8. The method of cooling and-ventilating an enclosure in which peo le assemble, which includes continuously wit drawing air from said enclosure for recirculation, permitting a portion of said air to be relieved into the outside atmosphere, mixing the remainder.

of said air with fresh air which has been admitted from the outside and is dehumidified and cooled before mixing with the withdrawn air, introducing the mixed'air into the enclosure, controlling the minimum temperature of the air introduced into said enclosure under the control of the temperature of the-air withdrawn from said enclosure, and controlling the maximum temperature and relative humidity in the enclosure hystatically under control of the humidrty of the air withdrawn from said enclosure,

9. The method of cooling and ventilatin an enclosure in which people assemble, whic includes withdrawing air from said enclosure, recirculating and returning to the enclosure at least a portion of said withdrawn air, mixing fresh air from the outside with said withdrawn air after said fresh air has been cooled and dehumidified and delivering themixed air to the enclosure, and regulating the proportions of said returned air and dehumidified air so that the temperature of mixed air introduced into said enclosure is not more than substantially 8 F. lower in temperature than the temperature in said'enclosure.

10. In an apparatus for ventilating an enclosure, the combination of an air dehumidifier having an inlet for outside fresh air, a mixing chamber connected with the outlet of said dehumidifier, a fan connected between said mixing chamber and said enclosure for drawing fresh air through said dehumidifier and mixing chamber and delivering the same to said enclosure, a second fan' for withdrawing air from said enclosure, a return air passage connectin the discharge of said second fan tosaid mixing chamber, means for the'relief of air from said enclosure to the outside atmosphere, means for varying the admission of fresh air to saiddehumidifier, and means-for correspondingly varying the relief of air from said enclosure. v

11. In, an apparatus for ventilatin chamber, means for the relief of air from saidv enclosure to the outside atmosphere means'for varying the admission of fresh air to said dehumidifier, and means for correspondingly varying the relief of air from said enclosure.

12. In an apparatus for ventilating an enclosure, the combination of an air dehumidifier having an inlet for outside fresh an enclosure, the combination for an air eh air, a mixing chamber connected with the outlet of said dehumidifier, a. fanfordrawmg fresh air through said dehumidifier and mixing chamber, branch air passa es conmeeting the discharge of said fan to iiferent portions of said enclosure, 9. second fan and suction connections for 'withdrawing air from said different portions of said enclosure, a return air passage connecting the discharge of said second fan to said mixing chamber, means for the relief of air from said enclosure to the outside atmosphere,

heaters in said branch air passages, thermostats insaid suction connections respectively controllin said heaters, a hygrostat in said return air passage, and mechanism controlled thereby for varying the admission of fresh air to the dehumidifier and correspondingly varying the relief of from sa d enclosure.

13. The method of ventilating and providing desired atmospheric conditions in an air enclosure in which people assemble, which includes conditioning fresh outside air to 1' provide air having a dew point below the dew o'int of the air in the enclosure, mixing air withdrawn from-the enclosure with said outside air after the latter is conditioned, introducing into the enclosure the mixed outside and withdrawn air, and permitting'the relief from the enclosure of volumcs of the air thereof substantially corresponding with the volumes 'of' outside air which are conditioned and introduced into the enclosure. I p

14. In an apparatus for ventilatingan'd providing desired atmospheric conditions in an enclosure in which people assemble, the combinationwith said enclosure'of means for permitting-relief of air therefrom in re.- stricted quantities, an air dehumidifier having an inlet for outside fresh air, a mixing chamber in communication with-the outlet of said dehumidifier, means between said mixing chamber and the enclosure for causing fresh air to be drawn through the dehumidifier and mixing chamber and insuring the delivery thereof into the enclosure r and also for returning air from the enclosure to said mixing chamber wherein it is mixed with the dehumidified air passing therethrough, and means for varying the ad-' mission of fresh air to said dehumidifier.

15. The. method of ventilating and providing desired atmosphericconditions in an en-' closure wherein people assemble, which ineludes the mixing together of two bodies of air having different dew point conditions,

one of said bodies being air withdrawn from the enclosure and the other of said bodies being fresh outside air, causing one of said bodies of air to be conditioned before said mixing of the air bodies to provide a dew point therein below the dew point of the air in the enclosure, delivering the mixed air so produced into the enclosure, permitting the for permitting relief of air therefrom in res'tricted quantities, an air dehumidifer, a blower between the dehumidifier and enclosure for forcing conditioned air into the en-. closure, an air chamber in communication for delivering two currents of air into the air chamber wherein they are mixed, one of said conduits extending to the enclosure for receiving air therefrom and the other extending to the outside atmosphere for receiving fresh air,.and wherein further, the condults are arranged to cause one of the currents of air to be passed through the dehumidifier to lower its dew point below the airin' the enclosure'and to cause the other of the currents of air to be delivered directly to the air chamber on the suction side of the blower without passing through the dehumidifier, and means for varying the amount of air admitted to said dehumidifier.

17. In an apparatus for ventilating and providing desired atmospheric conditions in an enclosure in which peopleassemble, the

combination with saidenclosure of means for permitting rellef of air therefrom in re-. stricted quantities, an air dehumidlfier,

means for producing two currents of air and after mixing them delivering the air mixture into the enclosure, means for causing one ofsaid air currents to be supplied from the enclosure and the other from the outside fresh air, conduit means for caus-.

45 with the suction side of the blower, conduits 

